From ffe302025ecdd937447d5ca4bb0fdbef6fe5a5f0 Mon Sep 17 00:00:00 2001
From: Sean Parkinson <sean@wolfssl.com>
Date: Mon, 23 Jan 2023 08:33:09 +1000
Subject: [PATCH] DSA: Don't force zero MPs on memory allocation failure

When memory allocation fails, the MPs are not initialized and force zero
is using invalid values.
---
 wolfcrypt/src/dsa.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/wolfcrypt/src/dsa.c b/wolfcrypt/src/dsa.c
index c3effccbd..7bc84111e 100644
--- a/wolfcrypt/src/dsa.c
+++ b/wolfcrypt/src/dsa.c
@@ -927,33 +927,33 @@ int wc_DsaSign(const byte* digest, byte* out, DsaKey* key, WC_RNG* rng)
 
 #ifdef WOLFSSL_SMALL_STACK
     if (k) {
-        if (ret != MP_INIT_E)
+        if ((ret != MP_INIT_E) && (ret != MEMORY_E))
             mp_forcezero(k);
         XFREE(k, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
     }
     if (kInv) {
-        if (ret != MP_INIT_E)
+        if ((ret != MP_INIT_E) && (ret != MEMORY_E))
             mp_forcezero(kInv);
         XFREE(kInv, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
     }
     if (r) {
-        if (ret != MP_INIT_E)
+        if ((ret != MP_INIT_E) && (ret != MEMORY_E))
             mp_clear(r);
         XFREE(r, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
     }
     if (s) {
-        if (ret != MP_INIT_E)
+        if ((ret != MP_INIT_E) && (ret != MEMORY_E))
             mp_clear(s);
         XFREE(s, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
     }
     if (H) {
-        if (ret != MP_INIT_E)
+        if ((ret != MP_INIT_E) && (ret != MEMORY_E))
             mp_clear(H);
         XFREE(H, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
     }
 #ifndef WOLFSSL_MP_INVMOD_CONSTANT_TIME
     if (b) {
-        if (ret != MP_INIT_E)
+        if ((ret != MP_INIT_E) && (ret != MEMORY_E))
             mp_forcezero(b);
         XFREE(b, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
     }